[Impeller] use optimal depth attachment, remove useless barrier.

impeller/renderer/backend/vulkan/BUILD.gn

@@ -16,6 +16,7 @@ impeller_component("vulkan_unittests") {
     "descriptor_pool_vk_unittests.cc",
     "driver_info_vk_unittests.cc",
     "fence_waiter_vk_unittests.cc",
+    "render_pass_builder_vk_unittests.cc",
     "render_pass_cache_unittests.cc",
     "resource_manager_vk_unittests.cc",
     "test/gpu_tracer_unittests.cc",

impeller/renderer/backend/vulkan/render_pass_builder_vk.cc

@@ -62,8 +62,8 @@ RenderPassBuilderVK& RenderPassBuilderVK::SetDepthStencilAttachment(
   desc.storeOp = ToVKAttachmentStoreOp(store_action);
   desc.stencilLoadOp = desc.loadOp;    // Not separable in Impeller.
   desc.stencilStoreOp = desc.storeOp;  // Not separable in Impeller.
-  desc.initialLayout = vk::ImageLayout::eGeneral;
-  desc.finalLayout = vk::ImageLayout::eGeneral;
+  desc.initialLayout = vk::ImageLayout::eUndefined;
+  desc.finalLayout = vk::ImageLayout::eDepthStencilAttachmentOptimal;
   depth_stencil_ = desc;
   return *this;
 }
@@ -80,8 +80,8 @@ RenderPassBuilderVK& RenderPassBuilderVK::SetStencilAttachment(
   desc.storeOp = vk::AttachmentStoreOp::eDontCare;
   desc.stencilLoadOp = ToVKAttachmentLoadOp(load_action);
   desc.stencilStoreOp = ToVKAttachmentStoreOp(store_action);
-  desc.initialLayout = vk::ImageLayout::eGeneral;
-  desc.finalLayout = vk::ImageLayout::eGeneral;
+  desc.initialLayout = vk::ImageLayout::eUndefined;
+  desc.finalLayout = vk::ImageLayout::eDepthStencilAttachmentOptimal;
   depth_stencil_ = desc;
   return *this;
 }
@@ -184,4 +184,19 @@ void InsertBarrierForInputAttachmentRead(const vk::CommandBuffer& buffer,
   );
 }
 
+const std::map<size_t, vk::AttachmentDescription>&
+RenderPassBuilderVK::GetColors() const {
+  return colors_;
+}
+
+const std::map<size_t, vk::AttachmentDescription>&
+RenderPassBuilderVK::GetResolves() const {
+  return resolves_;
+}
+
+const std::optional<vk::AttachmentDescription>&
+RenderPassBuilderVK::GetDepthStencil() const {
+  return depth_stencil_;
+}
+
 }  // namespace impeller

impeller/renderer/backend/vulkan/render_pass_builder_vk.h

@@ -42,6 +42,15 @@ class RenderPassBuilderVK {
 
   vk::UniqueRenderPass Build(const vk::Device& device) const;
 
+  // Visible for testing.
+  const std::map<size_t, vk::AttachmentDescription>& GetColors() const;
+
+  // Visible for testing.
+  const std::map<size_t, vk::AttachmentDescription>& GetResolves() const;
+
+  // Visible for testing.
+  const std::optional<vk::AttachmentDescription>& GetDepthStencil() const;
+
  private:
   std::map<size_t, vk::AttachmentDescription> colors_;
   std::map<size_t, vk::AttachmentDescription> resolves_;

impeller/renderer/backend/vulkan/render_pass_builder_vk_unittests.cc

@@ -0,0 +1,98 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "flutter/testing/testing.h"  // IWYU pragma: keep
+#include "gtest/gtest.h"
+#include "impeller/core/formats.h"
+#include "impeller/renderer/backend/vulkan/render_pass_builder_vk.h"
+#include "impeller/renderer/backend/vulkan/test/mock_vulkan.h"
+#include "vulkan/vulkan_core.h"
+#include "vulkan/vulkan_enums.hpp"
+
+namespace impeller {
+namespace testing {
+
+TEST(RenderPassBuilder, CreatesRenderPassWithNoDepthStencil) {
+  RenderPassBuilderVK builder = RenderPassBuilderVK();
+  auto const context = MockVulkanContextBuilder().Build();
+
+  // Create a single color attachment with a transient depth stencil.
+  builder.SetColorAttachment(0, PixelFormat::kR8G8B8A8UNormInt,
+                             SampleCount::kCount1, LoadAction::kClear,
+                             StoreAction::kStore);
+
+  auto render_pass = builder.Build(context->GetDevice());
+
+  EXPECT_TRUE(!!render_pass);
+  EXPECT_FALSE(builder.GetDepthStencil().has_value());
+}
+
+TEST(RenderPassBuilder, CreatesRenderPassWithCombinedDepthStencil) {
+  RenderPassBuilderVK builder = RenderPassBuilderVK();
+  auto const context = MockVulkanContextBuilder().Build();
+
+  // Create a single color attachment with a transient depth stencil.
+  builder.SetColorAttachment(0, PixelFormat::kR8G8B8A8UNormInt,
+                             SampleCount::kCount1, LoadAction::kClear,
+                             StoreAction::kStore);
+  builder.SetDepthStencilAttachment(PixelFormat::kD24UnormS8Uint,
+                                    SampleCount::kCount1, LoadAction::kDontCare,
+                                    StoreAction::kDontCare);
+
+  auto render_pass = builder.Build(context->GetDevice());
+
+  EXPECT_TRUE(!!render_pass);
+
+  auto maybe_color = builder.GetColors().find(0u);
+  ASSERT_NE(maybe_color, builder.GetColors().end());
+  auto color = maybe_color->second;
+
+  EXPECT_EQ(color.initialLayout, vk::ImageLayout::eGeneral);
+  EXPECT_EQ(color.finalLayout, vk::ImageLayout::eGeneral);
+  EXPECT_EQ(color.loadOp, vk::AttachmentLoadOp::eClear);
+  EXPECT_EQ(color.storeOp, vk::AttachmentStoreOp::eStore);
+
+  auto maybe_depth_stencil = builder.GetDepthStencil();
+  ASSERT_TRUE(maybe_depth_stencil.has_value());
+  auto depth_stencil = maybe_depth_stencil.value();
+
+  EXPECT_EQ(depth_stencil.initialLayout, vk::ImageLayout::eUndefined);
+  EXPECT_EQ(depth_stencil.finalLayout,
+            vk::ImageLayout::eDepthStencilAttachmentOptimal);
+  EXPECT_EQ(depth_stencil.loadOp, vk::AttachmentLoadOp::eDontCare);
+  EXPECT_EQ(depth_stencil.storeOp, vk::AttachmentStoreOp::eDontCare);
+  EXPECT_EQ(depth_stencil.stencilLoadOp, vk::AttachmentLoadOp::eDontCare);
+  EXPECT_EQ(depth_stencil.stencilStoreOp, vk::AttachmentStoreOp::eDontCare);
+}
+
+TEST(RenderPassBuilder, CreatesRenderPassWithOnlyStencil) {
+  RenderPassBuilderVK builder = RenderPassBuilderVK();
+  auto const context = MockVulkanContextBuilder().Build();
+
+  // Create a single color attachment with a transient depth stencil.
+  builder.SetColorAttachment(0, PixelFormat::kR8G8B8A8UNormInt,
+                             SampleCount::kCount1, LoadAction::kClear,
+                             StoreAction::kStore);
+  builder.SetStencilAttachment(PixelFormat::kS8UInt, SampleCount::kCount1,
+                               LoadAction::kDontCare, StoreAction::kDontCare);
+
+  auto render_pass = builder.Build(context->GetDevice());
+
+  EXPECT_TRUE(!!render_pass);
+
+  auto maybe_depth_stencil = builder.GetDepthStencil();
+  ASSERT_TRUE(maybe_depth_stencil.has_value());
+  auto depth_stencil = maybe_depth_stencil.value();
+
+  EXPECT_EQ(depth_stencil.initialLayout, vk::ImageLayout::eUndefined);
+  EXPECT_EQ(depth_stencil.finalLayout,
+            vk::ImageLayout::eDepthStencilAttachmentOptimal);
+  EXPECT_EQ(depth_stencil.loadOp, vk::AttachmentLoadOp::eDontCare);
+  EXPECT_EQ(depth_stencil.storeOp, vk::AttachmentStoreOp::eDontCare);
+  EXPECT_EQ(depth_stencil.stencilLoadOp, vk::AttachmentLoadOp::eDontCare);
+  EXPECT_EQ(depth_stencil.stencilStoreOp, vk::AttachmentStoreOp::eDontCare);
+}
+
+}  // namespace testing
+}  // namespace impeller

impeller/renderer/backend/vulkan/render_pass_vk.cc

@@ -113,7 +113,6 @@ SharedHandleVK<vk::RenderPass> RenderPassVK::CreateVKRenderPass(
         depth->load_action,                                   //
         depth->store_action                                   //
     );
-    TextureVK::Cast(*depth->texture).SetLayout(barrier);
   } else if (auto stencil = render_target_.GetStencilAttachment();
              stencil.has_value()) {
     builder.SetStencilAttachment(
@@ -122,7 +121,6 @@ SharedHandleVK<vk::RenderPass> RenderPassVK::CreateVKRenderPass(
         stencil->load_action,                                   //
         stencil->store_action                                   //
     );
-    TextureVK::Cast(*stencil->texture).SetLayout(barrier);
   }
 
   if (recycled_renderpass != nullptr) {